<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport"
        content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no">
    <title>材质_动态图片</title>
    <link href="../Build/Cesium/Widgets/widgets.css" rel="stylesheet" />
    <script src="../Build/Cesium/Cesium.js"></script>
    <style>
        html,
        body,
        #cesiumContainer {
            width: 100%;
            height: 100%;
            margin: 0;
            padding: 0;
            overflow: hidden;
        }

        .canvas {
            position: absolute;
            left: 10px;
            top: 10px;
            display: none;
        }

        #canvas-a {
            top: 10px;
        }

        #canvas-b {
            top: 120px;
        }
    </style>

</head>

<body>
    <div id="cesiumContainer"></div>
    <canvas id="canvas-a" class="canvas" width="700" height="100"></canvas>
    <canvas id="canvas-b" class="canvas" width="700" height="100"></canvas>
    <script>
        let osm = Cesium.createOpenStreetMapImageryProvider({
            url: 'https://a.tile.openstreetmap.org/'
        });
        let viewer = new Cesium.Viewer('cesiumContainer', {
            imageryProvider: osm,
            contextOptions: {
                webgl: {
                    alpha: true
                }
            },
            selectionIndicator: false,
            animation: false,  //是否显示动画控件
            baseLayerPicker: false, //是否显示图层选择控件
            geocoder: false, //是否显示地名查找控件
            timeline: false, //是否显示时间线控件
            sceneModePicker: false, //是否显示投影方式控件
            navigationHelpButton: false, //是否显示帮助信息控件
            infoBox: false,  //是否显示点击要素之后显示的信息
            fullscreenButton: false
        });
        //取消双击事件
        viewer.cesiumWidget.screenSpaceEventHandler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK);
        //设置homebutton的位置
        Cesium.Camera.DEFAULT_VIEW_RECTANGLE =
            Cesium.Rectangle.fromDegrees(110.15, 34.54, 110.25, 34.56);//Rectangle(west, south, east, north)
        //设置初始位置
        viewer.camera.setView({
            destination: Cesium.Cartesian3.fromDegrees(110.20, 34.55, 3000000)
        });

        //开启深度检测
        //viewer.scene.globe.depthTestAgainstTerrain = true;

        let curCanvas = 'a';
        let i = 0;
        function drawCanvasImage(time, result) {
            let canvas = document.getElementById("canvas-" + curCanvas);
            let cwidth = 700;
            let cheight = 100;
            let ctx = canvas.getContext("2d");
            let img = new Image();
            img.src = "../Source/Images/arrow.png";
            ctx.clearRect(0, 0, cwidth, cheight);
            img.onload = function () {
                if (i <= cwidth) {
                    ctx.drawImage(img, i, 0);
                } else
                    i = 0;
                i += 3;
            }
            curCanvas = curCanvas === 'a' ? 'b' : 'a';
            return canvas;
        }

        viewer.entities.add({
            name: 'Rotating rectangle with rotating texture coordinate',
            rectangle: {
                coordinates: Cesium.Rectangle.fromDegrees(-90.0, 30.0, -70.0, 35.0),
                height:100000,
                material: new Cesium.ImageMaterialProperty({
                    image: new Cesium.CallbackProperty(drawCanvasImage, false),
                    transparent: true
                })
            }
        });

        viewer.zoomTo(viewer.entities);

    </script>
</body>

</html>